SECTION I. — INTRODUCTION. 13 



It is the official policy of several of the largest companies at the 

 present time, to encourage this form of cultivation, and tlie number of 

 cane farmers has risen from about six thousand in 1900 to over twenty 

 thousand in 1918. 



HoM^ever desirable such multiplicity of small cultivators may be 

 from a political, social or financial aspect, it must be recognised that it 

 makes the organised control of diseases and pests of much greater 

 difficulty, and has a considerable influence on the methods which it is 

 possible to adopt for the reduction of disease. 



The cane is planted usually in the second half of the wet season 

 (August to November) and is not cut until the dry season of the second 

 year following, havin^; thus had about eighteen months growth. 

 Canes are known up to their first cutting as •' Plant Canes." which are 

 distinguished as " Wet Season Plants " if originally planted during 

 the wet weather or " Dry Season Plants" or '-Crop Plants" if planted, as 

 occasionally happens, during the dry season. These latter have only 

 about twelve months growth before the first cutting. Subsequent cuttings 

 take place every year and the canes are kno^vn as " 1st Uatoons" or 

 "2nd Ratoons" etc., according to the number of times they have been 

 cut. Canes older than third ratoons are not commonly seen and are 

 becoming each year less frequent. 



All the cutting and grinding has to be done in the dry weather 

 between January and the beginning of June, chiefly owing to the 

 impossibility of cartage on the traces or field roads during the 

 wet weather. 



THE BLIGHT. 



For many years the growing canes have been subject at irregular 

 intervals to serious damage by a disease or complex of diseases known 

 locally as "Blight." This consists, briefly, of a browning and drying up of 

 the leaves of the cane and a decay of the root system, which results in 

 more or less complete cessation of growth, an appearance throughout 

 the field "as if scorched by fire," and a loss ranging from a slight check 

 in growth to a complete destruction of the crop. 



In practically every case of blight the insect Tomaspis saccliarina 

 (Hemiptera, Cercopidae), known locally as the Sugar-cane Froghopper, 

 is found in numbers in the damaged areas, both on the leaves in the 

 winged adult stage, and on the roots where it lives in the young or 

 nymph stage surrounded by its characteristic white froth (Plate III.) 



In addition to the froghopper other diseases, chief of which are 

 those caused by various species of root fungi, are frequentl}' present in 

 the damaged canes and have been sometimes considered as responsible 

 for part at least of the destruction. 



The loss varies greatly from 3'ear to year and is difficult to estimate 

 with any exactness, particularly as it has been found, that many of the 

 causes of the prevalence of blight are unfavourable conditions which 

 would have themselves led to loss, even without the presence of the 

 froghopper and its associated diseases. 



Allowing for this, however, the loss in some j'ears is sufficiently 

 great to warrant the attention that it has attracted and to justify the 

 continuance of effort towards its understanding and control. 



